Acanthamoeba: A microscopic organism, an amoeba, found in soil, dust and fresh water (lakes, rivers, hot springs and hot tubs). Acanthamoeba also occur in brackish water and sea water as well as in heating, venting, and air conditioner units, humidifiers, and dialysis units.
Acanthamoeba can enter the skin through a cut, wound, or through the nostrils and, once inside the body, can travel to the lungs and through the bloodstream to other parts of the body, especially to the central nervous system (the brain and spinal cord). Through improper storage, handling, and disinfection of contact lenses, Acanthamoeba can enter the eye and there cause infection.
A particularly dire infection caused by Acanthamoeba called granulomatous amebic encephalitis is characterized by headache, stiff neck, nausea, vomiting, confusion, loss of balance, seizures, and coma that can progress over several weeks and end in death. Acanthamoeba infections occur more frequently in people with compromised immune systems and the chronically ill. Eye and skin infections are generally treatable while infections of the brain are almost always fatal.
- Abused inhalant
Abused inhalant: A breathable chemical vapor that is abused. All abused inhalants produce psychoactive (mind-altering) effects. Abused inhalants fall into the following categories: Solvents Industrial or household solvents or solvent-containing products, including paint thinners or removers, degreasers, dry-cleaning fluids, gasoline, and glue Art or office supply solvents, including correction fluids, felt-tip-marker fluid, and electronic contact […]
- Acanthosis nigricans
Acanthosis nigricans: A skin condition characterized by dark, thickened, velvety patches, especially in the folds of skin in the armpit, groin, and back of the neck. It can occur with endocrine diseases such as Cushing disease and diabetes mellitus, from tumors of the pituitary gland, underlying malignancies, certain drugs, and as a genetic disorder. It […]
- Abortion, artificial
Abortion, artificial: An abortion that is brought about intentionally. Also called an induced or therapeutic abortion. As opposed to a spontaneous abortion (a miscarriage).
Acaricide: An agent, usually a chemical, that kills mites. This class of pesticides is large and includes antibiotic acaricides, carbamate acaricides, formamidine acaricides, mite growth regulators, organophosphate acaricides, and many others. From the Latin acarus, a mite + -cide, to kill.
- Acanthamoeba keratitis
Acanthamoeba keratitis: Infection of the cornea by acanthamoeba, a microscopic water-borne ameba. The disease tends to occur in people who wear contact lens. It can accompany a bacterial infection of the eye. Acanthamoeba keratitis can produce corneal ulceration and result in severe loss of vision and even blindness. Signs and symptoms are persistent redness and […]